To improve power consumption efficiency, some processors may utilize power state setting which are referred to as “C” states. Each state may indicate a certain level of functionality. For example, C0 may indicate the processor is operating, C1 may indicate the processor is not executing instructions but may return to an executing state almost instantaneously, C2 may indicate the processor is to maintain all software-visible information but may take longer to return to full executing state, C3 may indicate the processor is sleep and does not need to keep its cache coherent, etc.
Various number of C states may be used by manufactures to designate these states. Generally, utilizing a lower processor power consumption state may involve a certain amount of overhead or inefficiency, for example, to prepare the processor hardware for entering a lower power consumption state and/or the delay associated with returning the processor hardware to a higher power consumption state.
Accordingly, how the various C states are utilized may have a direct impact on performance of a processor.